what rss feed to use with carp ?

[Brandon Sheley]

a client is wanting to pull some rss feeds from a few of his forums to different parts of his main site using CaRP, but we're running into issues getting the rss feed to work..
i use the external.php=rss but with the specific forums,, but it doesn't seem to pull any info,, when we look at the link site.com/extern.......rss I can see the feed, just when we use it with carp, nothing shows ?

any idea..

thank you